Given the equation 2square root of x minus 5 = 2, solve for x and identify if it is an extraneous solution.

1 answer

To solve the equation \( 2\sqrt{x} - 5 = 2 \), we will first isolate the square root term.

  1. Add 5 to both sides of the equation:

\[ 2\sqrt{x} = 2 + 5 \]

\[ 2\sqrt{x} = 7 \]

  1. Now divide both sides by 2:

\[ \sqrt{x} = \frac{7}{2} \]

  1. Next, square both sides to eliminate the square root:

\[ x = \left(\frac{7}{2}\right)^2 \]

\[ x = \frac{49}{4} \]

Now we have found a potential solution: \( x = \frac{49}{4} \).

Checking if this is an extraneous solution:

We need to substitute this value back into the original equation to verify that it satisfies the equation:

Original equation:

\[ 2\sqrt{x} - 5 = 2 \]

Substituting \( x = \frac{49}{4} \):

\[ 2\sqrt{\frac{49}{4}} - 5 = 2 \]

Calculate \( \sqrt{\frac{49}{4}} \):

\[ \sqrt{\frac{49}{4}} = \frac{7}{2} \]

Now substitute back into the equation:

\[ 2 \cdot \frac{7}{2} - 5 = 2 \]

This simplifies to:

\[ 7 - 5 = 2 \]

\[ 2 = 2 \]

Since both sides of the equation are equal, the solution \( x = \frac{49}{4} \) is valid and is not an extraneous solution.

Thus, the solution is:

\[ \boxed{\frac{49}{4}} \]